A motor vehicle drive unit for an electrical vehicle is usually connected to at least two driven wheels, one arranged at a respective side of the vehicle. Having two driven wheels arranged at a respective side of a vehicle normally makes it a requirement to provide a differential transmission in order to distribute torque equally between the driven wheels.
Additionally, vehicle weight to torque ratio and wheel diameter to top speed ratio usually means that at least a single speed two stepped reduction gear is required between the motor and each driven wheel. The reduction ratio of such a single speed reduction gear becomes a compromise between vehicle acceleration and top speed.
Further, limitations are also incurred by the motor rotor mechanical speed limits. These limitations affect the performance and usability of electric vehicles. One solution to the above would be to use a multi speed transmission. However, this usually incurs a higher cost and an increased weight.
Another solution is proposed by WO 2011042317, in which is proposed a motor vehicle drive unit for an electrical vehicle comprising an electric motor, a stator of which is rotatably mounted on two fixed supports joined to a frame of a vehicle. An axle shaft of a wheel is connected to a stator of the electric motor and an axle shaft of another other wheel is connected to a rotor of the electric motor. A rotation reversing device is provided to reverse the rotation of one of the two axle shafts of the wheels with respect to the rotation of the rotor or stator, respectively.
The electric motor proposed by WO 2011042317 may be of alternating current type and comprise a rotary electric contact to electrically connect the rotary stator to an electronic regulation unit. The electronic regulation unit may comprise a transformer to transform direct current of a battery into alternating current and an inverter to control the frequency of the alternating current sent to the electric motor. A respective reduction gear may be mounted such that an axle shaft on which a respective wheel is to be mounted protrudes therefrom.